The present invention relates to a 1-halo-(Z,E)-7,10-dodecadiene which is a novel compound and a method for the preparation of this compound. The compound is a useful intermediate for the synthesis of (Z,E)-9,12-tetradecadienyl acetate which is a sex pheromone of the insects belonging to the genus of Spodoptera as a kind of noxious pests in agriculture.
(Z,E)-9,12-Tetradecadienyl acetate is known as a sex pheromone of the insects belonging to the genus of Spodoptera and used for population control of the noxious insectan pest in agriculture. Several methods are known for the synthetic preparation of this compound including a method utilizing the Wittig reaction described in Japanese Patent Kokai 50-53312 and 50-58005 and Tetrahedron Letters, volume 1974, page 779, a method utilizing an organo-lithium compound described in Science, volume 170, page 542 (1970) and so on. These prior art methods, however, are not quite satisfactory in industrial productionof the compound because each of the methods involves a complicate process of synthesis and requires special and expensive starting materials.
Besides, a method utilizing a Grignard reaction is known for the synthesis of (Z,E)-9,12-tetradecadienyl acetate (see Bull. Soc. Chim. France, volume 1962, page 315 and volume 1963, page 1449). This method is also defective because of the low yield of the desired product and formation of a by-product by the allyl rearrangement reaction which can be separated from the reaction mixture only with great difficulties. Accordingly, it is eagerly desired to develop a novel and advantageous method for the industrial production of (Z,E)-9,12-tetradecadienyl acetate.
The extensive investigations undertaken with an object to solve the above mentioned problem have led to a discovery of a novel compound which can be used as an intermediate for the synthesis of (Z,E)-9,12-tetradecadienyl acetate without the above described problems and disadvantages in the prior art methods.